I did it years ago and had great results - lost weight, felt better, and had more energy - before the doctor said I probably had PCOS. I can't remember exactly how much weight I lost. It's so much easier to follow it than measuring every single food's glycemic index or load, than counting carbs, or (eek!) going carb free. It allowed for me to have a cookie with milk, corn, potatoes, pasta, etc. The only drawback is that it's very easy to make your carb option a piece of junk food, as long as you eat it with, lets say, a piece of chicken... Now that I'm having to go back to monitoring carbs, it's my go to eating plan. Give it a try, it's worth it! Note: I have no clue if the effectiveness of it is as good as low-GI/checking every food for GI at preventing diabetes or cutting insulin resistance, but it's a lot easier to stick to and that's always the hardest part.